CN1747300B - Method for adjusting or controlling resonance transducer and switch power device - Google Patents

Abstract

The resonant converter provides a resonant converter with a main bridge which is connected to an input signal. The resonant converter includes a converter at which an output signal can be taken; a resonant circuit and a regulating circuit. The converter is connected with the main bridge and the resonant circuit, the resonant circuit is further connected with the main bridge and the regulating circuit, and the regulating circuit is further connected with the main bridge.

Description

Method for regulating or controlling resonant converter and switching power supply device

technical field

The invention relates to a resonant converter, in particular to the control of the resonant converter and to a power supply unit with a resonant converter according to the invention. the

Background technique

A resonant converter usually includes two input terminals for applying the input voltage; two output terminals for providing the output voltage; and a resonant tank circuit which can be connected to the input voltage in accordance with its resonant frequency. The coil of the resonant tank circuit is inductively coupled to another coil which is connected to the two outputs via a rectifier circuit. the

A resonant converter is known from [1] in which defined separate voltages can be provided at at least two outputs which are designed to supply different amounts of power. the

A resonant converter is likewise known from [2], in which case an error signal of the converter output signal is used to influence the input signal of the resonant converter by means of a voltage-controlled oscillator (VCO). the

[3] describes a switched mode power supply with a resonant converter, according to which the resonant converter should provide an output voltage that is as constant as possible. For this purpose, a noise shaping filter (NSF) is inserted in the feedback branch. the

The resonant converters known from the prior art have the disadvantage that the output voltage of the secondary circuit, which is proportional to the input voltage of the resonant converter, is largely determined by the transformation ratio of the two coils in the resonant converter predetermined. Furthermore, the regulation efficiency of circuits such as those described in [2] is low, since the resonant current flows through all circuit components and must be designed for the corresponding operating capabilities. the

Contents of the invention

The object of the present invention is to provide a resonant converter capable of regulating the output voltage, in which the regulation of the output voltage is efficient and expensive components can be used without great effort. Furthermore, it is an object of the invention to provide the possibility of efficiently controlling a resonant converter and finally to provide a switched-mode power supply device with a resonant converter according to the invention. the

To solve this task, a method for regulating or controlling a resonant converter with:

a main bridge connected to the input signal, wherein the main bridge includes a first switch and a second switch connected in series with each other, wherein the input signal is applied to the series circuit formed by the first switch and the second switch,

a transformer having a primary coil and at least one secondary coil, wherein an output signal is obtainable on at least one secondary coil of said transformer,

A resonant tank comprising a resonant reactor having a first terminal and a second terminal, a capacitor having one end connected to the second terminal of the resonant reactor and the other end connected to the input signal, and a capacitor having one end connected to the resonant reactance A capacitor connected to the second terminal of the device and connected to the ground potential at the other end,

A regulating loop for regulating the output signal of the resonant converter, comprising a regulating reactor with a first terminal and a second terminal, wherein the second terminal of the regulating reactor is connected with the third switch and the fourth The intermediate points of the series circuit formed by the switch are connected, and the input signal is applied to the series circuit,

Wherein the input side of the primary coil of the transformer is connected to the intermediate point in the series circuit of the main bridge, and the output side of the primary coil is connected to the first terminal of the resonant reactor of the resonant circuit,

Wherein the second terminal of the resonant reactor of the resonant circuit is also connected with the first terminal of the regulating reactor of the regulating circuit,

In this case, the control loop is not actuated in a predeterminable first range, so that the control loop remains inactive while the proportional relationship between the output voltage signal and the input voltage signal remains unchanged. the

In addition, another method for adjusting or controlling a resonant converter is provided, wherein the structure and connection method of the resonant converter are the same as above, and the method includes the following steps:

- determining a voltage profile between the first switch and the second switch,

- the third switch is turned off simultaneously with a rising voltage edge of the voltage profile, and

- The fourth switch is switched off simultaneously with a falling voltage edge of the voltage profile. the

In addition, an alternative method for regulating or controlling a resonant converter is provided, wherein the resonant converter is constructed and connected in the same manner as described above, the method comprising the following steps:

- determining a voltage profile between the first switch and the second switch,

- the third switch is turned off simultaneously with a falling voltage edge of the voltage curve, and

- The fourth switch is switched off simultaneously with a rising voltage edge of the voltage profile. the

The present invention also provides a switching power supply device having a resonant converter having the same structure as above and operating according to the above method. the

Preferably, the input signal is switched on by flowing through the main bridge, so that the input signal is also connected to the resonant circuit and the control circuit in addition to the main bridge. the

It should be noted here that the output signal can be acquired at the converter, where it is preferably rectified and filtered after the converter. Depending on the requirements, the converter can thus provide an output signal, for example in particular as a filtered DC voltage. the

An improvement is that the main bridge comprises a first switch and a second switch connected in series with each other (series circuit), preferably, the ends of the first and second switches connected in series, that is to say a circuit consisting of the first and second switches The end of the series circuit, connected to the input signal and the resonant tank. Optionally, a midpoint between the first and second switches connected in series, ie a midpoint of the series circuit consisting of the first and second switches, is connected to the converter. the

Another improvement consists in that each or both of the first switch and the second switch are electronic switches. the

A further improvement is that the control loop includes a control bridge. In particular, the regulating bridge can comprise a third switch and a fourth switch, wherein optionally the third switch and the fourth switch are connected in series with one another. the

Another possible implementation is that the ends of the third switch and the fourth switch connected in series (that is, the series circuit composed of the third and fourth switches) are connected to the main bridge and the resonant tank. the

Optionally, the midpoint between the third and fourth switches connected in series (ie the midpoint of the series circuit between the third and fourth switches) is connected to the resonant tank via a regulating reactor. the

A further development consists in that the third switch and the fourth switch are each or both electronic switches. the

Wherein, at least one electronic switch, ie for example the first, second, third or fourth switch, may be a triode, a metal oxide semiconductor field effect transistor, a thyristor or an IGBT. In addition, any combination of different switches is also possible, for example, it is not necessary that all the switches are of the same type or of the same type. the

Another possibility consists in arranging a self-oscillating diode in parallel with a switch, in particular an electronic switch. Preferably, such a self-oscillating diode is already integrated, for example, in a metal-oxide-semiconductor field-effect transistor; in particular, however, it should be provided additionally, for example in conventional transistors. the

A further development is that the converter has at least one coil, preferably at least one transformer and/or a primary circuit and a secondary circuit. The primary circuit is preferably placed between the main bridge and the resonant circuit. In addition, the output signal can be obtained via a secondary loop. the

A refinement consists in that the resonant tank has at least one coil and/or at least one capacitor. The resonant tank preferably includes a coil and a capacitor. the

In a further preferred embodiment, the resonant tank has two capacitors connected in series. Wherein, the ends of the capacitors connected in series, that is, the ends of the circuit composed of two capacitors, can be respectively connected to the main bridge and the regulating circuit. Preferably, that is to say if the main bridge is constructed such that the input signal connected to it is switched through it, the ends of the capacitors connected in series can be connected to the input signal, that is to say in this case the input signal is additionally fed by two provided on a circuit consisting of series capacitors. the

Another improvement is that the midpoint of the series circuit consisting of two capacitors is connected to the converter via a resonant reactor. Furthermore, this midpoint can likewise be connected to the control loop. the

An alternative embodiment is that the input signal is respectively connected to the main bridge, the resonant tank and the regulating circuit. the

Preferably, the input signal can be smoothed by means of at least one input capacitor. the

An improvement is that the input signal is an input voltage and/or the output signal is an output voltage. the

A further improvement consists in that the output signal is rectified downstream of the transformer by means of at least one diode and preferably smoothed by means of at least one output capacitor. Various rectification devices can be provided here, for example a bridge rectifier circuit which generally smooths the rectified signal accordingly. the

Furthermore, to solve this object, a method for regulating or controlling a resonant converter is provided, in which the control loop of the resonant converter is not controlled in a first predeterminable range. Here the resonant converter is implemented in particular as described above, if the proportional relationship between the output voltage and the input voltage remains unchanged, the control loop can remain inactive, ie no control of the control bridge, in particular the third and third Four switches. In this mode of operation, therefore, no regulation losses occur. the

A further optional embodiment of the control loop control consists in the detection of, for example, a measurement of the voltage change between the first switch and the second switch. The third switch is preferably switched off substantially simultaneously with a rising voltage edge of the (ascertained) voltage profile. Optionally, the third switch is switched on substantially (in time) before a rising voltage edge of the voltage profile. Preferably, the fourth switch can be switched off substantially simultaneously with a falling voltage edge of the voltage profile. Furthermore, the fourth switch can be switched substantially (temporally) before a falling voltage edge of the voltage profile. the

The earlier the third and fourth switches are switched on within the time interval provided for this, the stronger the upregulation of the resonant converter, ie the greater the voltage ratio of the output signal to the input signal. The control is therefore suitable for increasing the output voltage of the resonant converter. the

Another alternative consists in downregulation, ie in reducing the voltage ratio of the output signal to the input signal and thus reducing the output voltage of the resonant converter. the

Related to this is the preferably ascertainment (for example measurement) of the voltage profile between the first switch and the second switch. The third switch can then be switched off substantially simultaneously with a falling voltage edge of the voltage profile. The third switch is preferably switched on substantially (in time) before a falling voltage edge of the voltage profile. To supplement this, the fourth switch can be switched off substantially simultaneously with a rising voltage edge of the voltage curve, preferably switched on substantially (in time) before a rising voltage edge of the voltage curve. the

Furthermore, there is provided a power supply, in particular a power supply device, more particularly a switching power supply device, comprising a resonant converter as described above. The resonant converter in the switching power supply device preferably operates as described above. the

Description of drawings

Embodiments of the present invention are shown and described below with reference to the accompanying drawings. the

Figure 1 shows a block diagram of a resonant converter;

Figure 2 shows the circuit of the resonant converter;

Figure 3 is a timing diagram illustrating the control of the main bridge of the resonant converter;

Figure 4 is a timing diagram illustrating the control of the regulation bridge for up-regulating (Fig. 4A) and down-regulating resonant converters;

Figure 5 is an oscillogram illustrating downregulation;

Fig. 6 is an oscillogram illustrating the adjustment;

Fig. 7 shows a block diagram of a switching power supply device with a resonant converter. the

Detailed ways

Figure 1 shows a block diagram of a resonant converter. The input signal Vin is connected to the main bridge 110 through the input terminals 104 and 105 . The inputs 104 and 105 can be realized, for example, as input terminals, terminals or pins. Preferably, the input 105 may be at ground potential, so that the input 104 specifically has an input signal +/- Vin (relative to ground). the

The main bridge 110 is further connected to a converter 120 , a resonant tank 130 and a regulating tank 140 . Preferably, the input signal Vin applied via the input terminals 104 and 105 passes through the main bridge 110 and is connected to the resonant circuit 130 and the regulating circuit 140 as the input signal Vin. the

Converter 120 is also connected to resonant tank 130 . An output signal Vout is available at the output side of the converter 120. Preferably, the output signal Vout is rectified and smoothed after the converter 120 . In FIG. 1, two diodes 101 and 102 are provided as an example for rectification, and an output capacitor 103 is arranged in parallel with the output signal Vout. The output capacitor 103 is preferably realized as an electrolytic capacitor (ELKO). The output signal Vout is provided via output terminals 106 and 107 , wherein output terminal 107 preferably has a positive potential relative to output terminal 106 . the

Instead of the two diodes 101 and 102 , other rectifiers can also be selected, for example metal-oxide-semiconductor field-effect transistors. The possibility of using a bridge rectifier is not excluded here. the

Resonant circuit 130 is also connected to converter 120 and control circuit 140 . the

The detailed circuit of each component 110, 120, 130 and 140, especially the cooperation relationship with each other is shown in FIG. 2 by way of example. the

In FIG. 2, the input signal Vin is applied through the input terminals 104 and 105, so that the input terminal 105 has the ground potential, and the input terminal 104 has the potential Vin. An input capacitor 201 may be provided in parallel with the input signal Vin. the

The main bridge 110 is connected in parallel with the input signal Vin, wherein a first MOSFET V1 and a second MOSFET V2 are connected in series between the input terminal 104 and the input terminal 105 (here: ground potential) . A metal-oxide-semiconductor field-effect transistor is an example of an electronic switch; alternatively, other electronic switches, in particular IGBTs or triodes, can also be used here. the

All electronic switches in Figure 2 are implemented with n-channel enhancement-mode metal-oxide-semiconductor field-effect transistors. The terminals of each metal oxide semiconductor field effect transistor are denoted below using a gate terminal, an S terminal for "source", and a D terminal for "drain". the

It should be noted that basically a self-oscillating diode can be connected in parallel for each electronic switch. However, this can be omitted in many electronic switches already integrating such free-running diodes (for example in metal-oxide-semiconductor field-effect transistors). In principle, it is also possible to connect a capacitor in parallel with the electronic switch in order to reduce the speed of voltage fluctuations. the

A series circuit consisting of a first Mosfet V1 and a second Mosfet V2 connects the two electronic switches V1 and V2 such that the S connection of the first Mosfet V1 The terminal is connected to the ground potential (that is, the input terminal 105 of the input signal Vin). The D terminal of the first MOSFET V1 is connected to the S terminal of the second MOSFET V2, and the D terminal of the second MOSFET V2 is connected to the input signal Vin The input terminal 104 is connected. The midpoint of the two electronic switches is represented by "Drain 1". the

The converter 120 includes a transformer T1 composed of a primary winding 202 and secondary windings 203 and 204 . The secondary coils 203 and 204 are connected in series. The midpoint of the coils 203 and 204 is represented as the output 106 of the output signal Vout. The ends of the series circuit consisting of the two secondary coils 203 and 204 lead respectively to the anode of diode 102 (connected to coil 203) and to the anode of diode 101 (connected to coil 204), where the cathodes of diodes 101 and 102 are connected to each other , and connected to terminal 107. The output signal Vout can thus be obtained via the terminals 106 and 107 , wherein an electrolytic capacitor 103 is connected in parallel to the terminals 106 and 107 , the positive charging terminal of which is connected to the terminal 107 . the

The midpoint of the first MOSFET V1 and the second MOSFET V2 , that is, “drain 1 ” is connected to one end of the primary coil 202 of the converter 120 . the

The other end of the primary coil 202 is connected to the resonant tank 130 and also connected to one end of the resonant reactor L1. The other end of the resonant reactor L1 is connected to the midpoint Vres of the series circuit composed of the first resonant capacitor C1 and the second resonant capacitor C2. The other end of the first resonant capacitor C1 is connected to the terminal 104 of the input signal Vin, and the other end of the second resonant capacitor C2 is connected to the terminal 105 of the input signal Vin (ie, to the ground potential). Another alternative is to omit one of the two capacitors. In addition, the resonant reactor L1 can also be formed by the leakage inductance of the transformer. the

A midpoint Vres between the two resonant capacitors C1 and C2 is connected to the regulation loop 140 and is connected to one end of the regulation reactor L2. In FIG. 2 , the regulation loop 140 is implemented as a regulation bridge composed of two electronic switches, here two n-channel enhancement MOSFETs V3 and V4. The same applies for the two mosfets V3 and V4 as for the mosfets V1 and V2 . the

The third MOSFET V3 and the fourth MOSFET V4 are connected in series such that the S terminal of the third MOSFET V3 is connected to the terminal 105 (ground) of the input signal Vin. potential) connection, the D terminal of the third MOSFET V3 is connected to the S terminal of the fourth MOSFET V4 and the other end of the adjusting reactor L2. This position is also indicated as the midpoint "drain 3" of the series circuit formed by the third Mosfet V3 and the fourth Mosfet V4. The D terminal of the fourth MOSFET V4 is connected to the terminal 104 of the input signal Vin. the

It should be noted here that the input signal Vin and the output signal Vout are preferably the input voltage and the output voltage. the

Figure 3 shows a timing diagram illustrating the control of the main bridge of the resonant converter. the

As shown in FIG. 2, the main bridge 110 of the resonant converter includes electronic switches V1 and V2, which are connected to resonant capacitors C1 and C2 via a transformer T1 (primary coil 202 and secondary coils 203 and 204) and a resonant reactor L1 . At this point, ie at the midpoint Vres between the two resonant capacitors C1 and C2, an essentially sinusoidal resonant voltage 301 occurs. the

The first Mosfet V1 and the second Mosfet V2 are normally switched on alternately with a small control pause, so that the The midpoint of the series circuit composed of the effect transistor V1 and the second metal oxide semiconductor field effect transistor V2 realizes voltage transition. In FIG. 2 the characteristic curve 303 represents the control of the first MOSFET V1 and the characteristic curve 304 represents the control of the second MOSFET V2. the

The MOSFET is usually controlled via its gate terminal, that is to say an external control circuit controls, for example, the gate terminal of each MOSFET in dependence on the remaining characteristic quantities of the individual circuits. voltage changes on the the

In the present case (circuit according to FIG. 2 ), from the control of the first Mosfet V1 according to the characteristic curve 303 and from the control of the second Mosfet V2 according to the characteristic curve 304 The control produces a voltage profile at "drain 1" according to characteristic curve 302 . the

At time t1, the first MOSFET V1 is “off” (see characteristic curve 303 ), and the voltage change curve 302 rises. At time t2, the second mosfet V2 is “on” (see characteristic curve 304 ), the voltage profile 302 remains almost constant at a high potential until at the next time t3 the second mosfet V2 (characteristic curve 304 ) is "OFF". The voltage on "Drain 1 " (see characteristic curve 302 ) now drops until time t4 the first Mosfet "switches on" and thus the voltage on Drain 1 remains almost constant at a low potential. the

The voltage curve 301 at the midpoint Vres is substantially sinusoidal, and the voltage curve 302 "drain 1" has a phase shift of 90° relative to it. the

The output voltage Vout of the resonant converter is when the voltage drop in the circuit is ignored:

Vout＝Vin/(2*ue) (1)

in,

ue=n _prim /n _sek (2)

inferred:

Vout is proportional to Vin

in,

ue represents the transformation ratio of the transformer,

n _prim represents the number of turns of the primary coil of the transformer, and

n _sek represents the number of turns of the secondary coil of the transformer.

By modulating the curve shape and/or the amplitude of the voltage change at the midpoint Vres by means of the control loop 140 (see characteristic curve 301 ), it is possible to adjust the otherwise fixed ratio of Vout/Vin to a defined range. Thus, for example, a constant output voltage Vout can be achieved over a defined range of the input voltage Vin. the

For regulation, three cases are distinguished in particular:

- Neutral zone: Vout/Vin corresponds to the formula (1) remains unchanged;

- Up regulation: Vout/Vin rises;

- Down regulation: Vout/Vin decreases. the

The maximum upregulation is achieved, for example, in the following cases:

- the voltage profile at the point "drain 1" changes in phase with the voltage profile at the point "drain 3";

- the voltage profile at the gate terminal of the first MOSFET V1 is in particular equal to the voltage profile at the gate terminal of the third MOSFET V3, additionally the second MOSFET The voltage profile at the gate terminal of the semiconductor field effect transistor V2 is in particular equal to the voltage profile at the gate terminal of the fourth metal oxide semiconductor field effect transistor V4, that is: U _Gate1 = U _Gate3 and U _Gate2 = U _Gate4 .

The maximum downregulation is achieved, for example, in the following cases:

- the voltage curve at the point "drain 1" changes in antiphase to the voltage curve at the point "drain 3";

- the voltage profile at the gate terminal of the first MOSFET V1 is in particular equal to the voltage profile at the gate terminal of the fourth MOSFET V4, additionally the second MOSFET The voltage profile at the gate terminal of the semiconductor field effect transistor V2 is in particular equal to the voltage profile at the gate terminal of the third MOSFET V3, that is: U _Gate1 = U _Gate4 and U _Gate2 = U _Gate3 .

The region between maximum down-regulation and up-regulation can be done by a phase shift (whether before or after) from the voltage at point "Drain 3" relative to the voltage at point "Drain 1". The disadvantage here is that in the range of small up or down adjustments or at low loads there are large changes in the control losses and the resonance frequency. An improved embodiment is described below. the

Preferably, in the above-mentioned “neutral zone”, ie if the proportional relationship Vout/Vin according to formula (1) is to be maintained, no further regulation by the regulation loop 140 is carried out. In particular in this neutral range, the control circuit is not activated in order to avoid additional losses. the

In contrast, if downregulation or upregulation is to be performed, the control bridge is controlled as required, in particular via the third MOSFET V3 and the fourth MOSFET V4 . This reduces the current in control reactor L2 compared to control with a phase shift, which leads to reduced losses through control loop 140 . the

In this control of control loop 140 there is preferably a dead time during which neither third Mosfet V3 nor fourth Mosfet V4 is actuated. the

FIG. 4 is a timing diagram illustrating regulation up control (FIG. 4A) and regulation down control (FIG. 4B) of the regulation bridge of the resonant converter. the

In both cases of up-regulation (FIG. 4A) and down-regulation (FIG. 4B), when the third MOSFET It is particularly advantageous to switch off V3 and the fourth Mosfet V4 in order to thereby advantageously minimize the reactive current for regulation. the

Figure 4A shows the case of upregulation. The voltage curve 401 at the point "drain 1" of the circuit according to FIG. The voltage curve 403 , which is controlled by the gate connection of the MOSFET V4 , is opposite. the

In this case, the third MOSFET V3 is switched off at time T2 substantially simultaneously with the rising voltage edge of the voltage profile 401 . Preferably, the third MOSFET V3 is turned on at time T1 before the voltage rising edge of the voltage change curve 401 . the

This switch-on moment of the third Mosfet V3 is variable in time with respect to the switching point of the main bridge (eg point “drain 1 ”, represented by the voltage curve 401 ). With this switching moment the magnitude of the Vout/Vin change forced by regulation can be adjusted. In FIG. 4A the variable switching times relative to the switching on of the third Mosfet V3 are indicated by arrows 407 and 408, while the variable switching times relative to the switching on of the fourth Mosfet V4 The switching moments are indicated by arrows 409 and 410 . the

In particular, the fourth MOSFET V4 is switched off at time T4 at the same time as a voltage falling edge of the voltage curve 401 . Preferably, the fourth MOSFET V4 is switched on at time T3 before a voltage falling edge of the voltage curve 401 . the

Figure 4B shows the case of downregulation. The voltage curve 404 corresponds to the voltage curve 401 in FIG. 4A at the point “drain 1 ” of the circuit according to FIG. 2 . The voltage curve 405 controlled by the gate terminal of the third MOSFET V3 and the voltage curve controlled by the gate terminal of the fourth MOSFET V4 406 is opposite to the voltage curve 404 . the

In this case, the third MOSFET V3 is switched off substantially simultaneously with the falling voltage edge of the voltage curve 404 , or in particular at time T4 . Preferably, the third MOSFET V3 is switched on at time T3 before the voltage falling edge of the voltage change curve 404 . the

This switch-on instant of the third Mosfet V3 is variable in time relative to the switching point of the main bridge (eg point “drain 1 ”, represented by the voltage curve 404 ). With the aid of this switching moment, the magnitude of the Vout/Vin change forced by regulation can be adjusted. In FIG. 4B the variable switching times relative to the switching on of the third Mosfet V3 are indicated by arrows 411 and 412, while the variable switching times relative to the switching on of the fourth Mosfet V4 The switching times are indicated by arrows 413 and 414 . the

In particular, the fourth MOSFET V4 is switched off at time T2 simultaneously with a rising voltage edge of voltage profile 404 . Preferably, the fourth MOSFET V4 is switched on at time T1 before a rising voltage edge of the voltage curve 404 . the

In the neutral region, preferably no control pulses are present at the gate connection of the third MOSFET V3 and/or the fourth MOSFET V4. the

Figure 5 shows an oscillogram illustrating the mode of operation of the adjustment. To this end, FIG. 5 shows a voltage curve 501 at the point "drain 1" between the first MOSFET V1 and the second MOSFET V2, a voltage curve 501 through the resonant reactor L1 A current curve 502, a voltage change curve 503 at the point "drain 3" between the third MOSFET V3 and the fourth MOSFET V4, and a voltage variation curve 503 at the point "drain 3" between the third MOSFET The voltage change curve 504 on the gate terminal of the semiconductor field effect transistor V3. the

The voltage curve 503 represents the transition to the input voltage level after switching off the gate pulse of the third MOSFET V3 , ie after the falling edge of the voltage curve 504 . The voltage remains applied there until the regulating reactor L2 is demagnetized and the current through it disappears. During this demagnetization 510, current flows in reverse through the body diode of the fourth MOSFET V4. Alternatively and/or additionally, the fourth MOSFET V4 may also be controlled during this period to unload the body diode. This applies in particular to all switches of the resonant converter. the

How long the regulating reactor L2 is required for demagnetization 510 depends in particular on the duration of the voltage pulse at the gate connection of the third MOSFET V3 and the voltage on the regulating reactor L2. Here too, the voltage across the regulating reactor L2 is influenced by the output current. the

Figure 6 shows an oscillogram illustrating the mode of operation of the upregulation. To this end, FIG. 6 shows a voltage curve 601 at the point "drain 1" between the first MOSFET V1 and the second MOSFET V2, a voltage curve 601 through the resonant reactor L1 A current curve 602, a voltage change curve 603 at the point "drain 3" between the third MOSFET V3 and the fourth MOSFET V4, and a voltage variation curve 603 at the point "drain 3" between the third MOSFET The voltage change curve 604 on the gate terminal of the semiconductor field effect transistor V3. the

In particular, the duration of the demagnetization 610 at no load is the same as the duration of the control pulse 611 . The duration of the demagnetization 610 at high loads is shorter for upregulation and longer for downregulation. This is a result of voltage fluctuations across the resonant capacitor as the load rises. the

An additional RC circuit is preferably used to attenuate fluctuations in voltage profile 603 during standstill. the

In the case of a longer-lasting control 611 (wider control pulse), control 611 and demagnetization 610 occur or are superimposed. In this case, there is no longer any pause. the

It should be noted here that the adjustment area depends on the size of the adjustment reactor L2: the smaller the inductance of L2, the larger the adjustment range. the

The resonant converter described above can be used particularly advantageously in a power supply unit, in particular a power supply unit with a power supply or a switched-mode power supply, in the above-described manner of operation or control. Preferably, the control loop 140 is used to influence a constant output voltage, or to adjust the above-mentioned neutral zone up or down to a predetermined range. the

Fig. 7 shows a block diagram of a switching power supply device with a resonant converter. Here, an input signal 701 is converted into an output signal 709, preferably an alternating voltage into a controlled direct voltage. The input signal 701 is input to a block 702 with network rectification and smoothing. The output signal of module 702 is directed to resonant converter 703 , which includes a main bridge 704 and a regulation bridge 705 . The output signal of resonant converter 703 corresponds to output signal 709 , wherein this output signal is led to regulator 706 . The signal obtained by the regulator 706 is passed to a controller or pulse width modulator 707 , wherein an output signal of the controller or pulse width modulator 707 influences the regulating bridge 705 of the resonant converter 703 . In addition, an oscillator 708 is provided which supplies signals both to the controller or pulse width modulator 707 and to the main bridge 704 of the resonant converter 703 . the

Bibliography

[1]EP 1 303 032 A2

[2]US 2003/0147263 A1

[3]DE 100 60 169 A1

Claims (10)

1. Method for regulating or controlling a resonant converter having: a main bridge (110) connected to an input signal (Vin), wherein said main bridge (110) comprises a first switch (V1) and a second switch (V2) connected in series with each other, wherein the input signal (Vin) is Applied to the series circuit formed by the first switch (V1) and the second switch (V2), A transformer (120) having a primary winding (202) and at least one secondary winding (203, 204), wherein an output signal (Vout ), A resonant circuit (130), comprising a resonant reactor (L1) having a first terminal and a second terminal, one end is connected to the second terminal of the resonant reactor (L1) and the other end is connected to the input signal (Vin ), and a capacitor (C2) connected at one end to the second terminal of said resonant reactor (L1) and at the other end to ground potential, A regulating loop (140), comprising a regulating reactor (L2) with a first terminal and a second terminal, wherein the second terminal of the regulating reactor (L2) is connected to the third switch (V3) and the fourth The intermediate point of the series circuit formed by the switch (V4) to which the input signal (Vin) is applied is connected, Wherein the input side of the primary coil (202) of the transformer (120) is connected to the intermediate point in the series circuit of the main bridge (110), and the output side of the primary coil is connected to the resonant reactor of the resonant circuit (130) (L1) connected to the first terminal, Wherein the second terminal of the resonant reactor (L1) of the resonant circuit (130) is also connected to the first terminal of the regulating reactor (L2) of the regulating circuit (140), In this case, the control loop (140) is deactivated in a first predeterminable range, so that the control loop remains inactive while the proportional relationship between the output signal and the input signal remains unchanged. 2. Method for regulating or controlling a resonant converter having: a main bridge (110) connected to an input signal (Vin), wherein said main bridge (110) comprises a first switch (V1) and a second switch (V2) connected in series with each other, wherein the input signal (Vin) is Applied to the series circuit formed by the first switch (V1) and the second switch (V2), A transformer (120) having a primary winding (202) and at least one secondary winding (203, 204), wherein an output signal (Vout ), A resonant circuit (130), comprising a resonant reactor (L1) having a first terminal and a second terminal, one end is connected to the second terminal of the resonant reactor (L1) and the other end is connected to the input signal (Vin ), and a capacitor (C2) connected at one end to the second terminal of said resonant reactor (L1) and at the other end to ground potential, A regulating loop (140), comprising a regulating reactor (L2) with a first terminal and a second terminal, wherein the second terminal of the regulating reactor (L2) is connected to the third switch (V3) and the fourth The intermediate point of the series circuit formed by the switch (V4) to which the input signal (Vin) is applied is connected, Wherein the input side of the primary coil (202) of the transformer (120) is connected to the intermediate point in the series circuit of the main bridge (110), and the output side of the primary coil is connected to the resonant tank (130) The first terminal of the resonant reactor (L1) is connected, Wherein the second terminal of the resonant reactor (L1) of the resonant circuit (130) is also connected to the first terminal of the regulating reactor (L2) of the regulating circuit (140), The method comprises the steps of: - determining a voltage profile between the first switch (V1) and the second switch (V2), - the third switch (V3) is switched off simultaneously with a rising voltage edge of the voltage profile, and - The fourth switch ( V4 ) is switched off simultaneously with a falling voltage edge of the voltage profile. 3. The method as claimed in claim 2, wherein the third switch (V3) is switched on before the rising voltage edge of the voltage profile. 4. The method as claimed in claim 2, wherein the fourth switch (V4) is switched on before the falling voltage edge of the voltage profile. 5. The method according to claim 2, for up-regulating the voltage ratio of the output signal (Vout) to the input signal (Vin). 6. Method for regulating or controlling a resonant converter having: a main bridge (110) connected to an input signal (Vin), wherein said main bridge (110) comprises a first switch (V1) and a second switch (V2) connected in series with each other, wherein the input signal (Vin) is Applied to the series circuit formed by the first switch (V1) and the second switch (V2), A transformer (120) having a primary winding (202) and at least one secondary winding (203, 204), wherein an output signal (Vout ), A resonant circuit (130), comprising a resonant reactor (L1) having a first terminal and a second terminal, one end is connected to the second terminal of the resonant reactor (L1) and the other end is connected to the input signal (Vin ), and a capacitor (C2) connected at one end to the second terminal of said resonant reactor (L1) and at the other end to ground potential, A regulating loop (140), comprising a regulating reactor (L2) with a first terminal and a second terminal, wherein the second terminal of the regulating reactor (L2) is connected to the third switch (V3) and the fourth The intermediate point of the series circuit formed by the switch (V4) to which the input signal (Vin) is applied is connected, Wherein the input side of the primary coil (202) of the transformer (120) is connected to the intermediate point in the series circuit of the main bridge (110), and the output side of the primary coil is connected to the resonant tank (130) The first terminal of the resonant reactor (L1) is connected, Wherein the second terminal of the resonant reactor (L1) of the resonant circuit (130) is also connected to the first terminal of the regulating reactor (L2) of the regulating circuit (140), The method comprises the steps of: - determining a voltage profile between the first switch (V1) and the second switch (V2), - the third switch (V3) is switched off simultaneously with a falling voltage edge of the voltage profile, and - The fourth switch ( V4 ) is switched off simultaneously with a rising voltage edge of the voltage curve. 7. The method as claimed in claim 6, wherein the third switch (V3) is switched on before the falling voltage edge of the voltage profile. 8. The method as claimed in claim 6 or 7, wherein the fourth switch (V4) is switched on before the rising voltage edge of the voltage curve. 9. The method according to claim 6, for downregulating the voltage ratio of the output signal (Vout) to the input signal (Vin). 10. A switching power supply device with a resonant converter having: a main bridge (110) connected to an input signal (Vin), wherein said main bridge (110) comprises a first switch (V1) and a second switch (V2) connected in series with each other, wherein the input signal (Vin) is Applied to the series circuit formed by the first switch (V1) and the second switch (V2), A transformer (120) having a primary winding (202) and at least one secondary winding (203, 204), wherein an output signal (Vout ), A resonant circuit (130), comprising a resonant reactor (L1) having a first terminal and a second terminal, one end is connected to the second terminal of the resonant reactor (L1) and the other end is connected to the input signal (Vin ), and a capacitor (C2) connected at one end to the second terminal of said resonant reactor (L1) and at the other end to ground potential, A regulating loop (140), comprising a regulating reactor (L2) with a first terminal and a second terminal, wherein the second terminal of the regulating reactor (L2) is connected to the third switch (V3) and the fourth The intermediate point of the series circuit formed by the switch (V4) to which the input signal (Vin) is applied is connected, Wherein the input side of the primary coil (202) of the transformer (120) is connected to the intermediate point of the series circuit of the main bridge (110), and the output side of the primary coil is connected to the resonant tank (130) The first terminals of the resonant reactor (L1) are connected, Wherein the second terminal of the resonant reactor (L1) of the resonant circuit (130) is also connected to the first terminal of the regulating reactor (L2) of the regulating circuit (140), wherein said resonant converter is operated using a method according to one of claims 1 , 2 , 6 and 8 .

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